Scientists discover brain mechanism for sugar cravings

Reaching for sweet treats may be rooted in a specific biological mechanism of the brain, according to new research from Imperial College London.

While normally it's said that cravings for starchy foods are part of our evolutionary makeup - carb-rich nutrients give us energy and provide feelings of well-being - the study suggests that a certain enzyme, glucokinase, could be the driving force behind the desire for sugar.

"This is the first time anyone has discovered a system in the brain that responds to a specific nutrient, rather than energy intake in general," said Dr. James Gardiner, lead study author. "It suggests that when you're thinking about diet, you have to think about different nutrients, not just count calories."

A potential obesity drug?

For the study, researchers found that rats who fasted for 24 hours had significant changes in areas of the hypothalamus that regulate appetite, as well as the glucokinase activity observed there.

After researchers increased the glucokinase activity by injecting the rats with a virus, the rodents consumed more glucose than when their glucokinase activity was decreased.

In the future, it's possible that a drug could be developed to help act on this enzyme and potentially prevent behaviors like overeating.

"People are likely to have different levels of this enzyme, so different things will work for different people," Dr. Gardiner said. "For some people, eating more starchy foods at the start of a meal might be a way to feel full more quickly by targeting this system, meaning they eat less overall."

Source: Imperial College London